<template>

  <div class="app-container">

    <h2 style="text-align: center;">发布新课程</h2>

    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>

    <el-form label-width="120px">

      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
      </el-form-item>

      <!-- 所属分类 TODO -->
      <el-form-item label="课程分类">
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="一级分类" @change="subjectLevelOneChanged">

          <el-option
            v-for="subject in subjectOneList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>

        </el-select>

        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="二级分类">
          <el-option
            v-for="subject in subjectTwoList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
      </el-form-item>


      <!-- 课程讲师 TODO -->
      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select
          v-model="courseInfo.teacherId"
          placeholder="请选择">

          <el-option
            v-for="teacher in Teacher"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"/>

        </el-select>
      </el-form-item>

      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
      </el-form-item>

      <!-- 课程简介 TODO -->
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description" />
      </el-form-item>


      <!-- 课程封面 TODO -->
      <!-- 课程封面-->
      <el-form-item label="课程封面">
        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API+'/eduoss/fileoss'"
          class="avatar-uploader">
          <img :src="courseInfo.cover">
        </el-upload>
      </el-form-item>


      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/> 元
      </el-form-item>

      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="next">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>

<script>
import course from '@/api/edu/course'
import subject from '@/api/edu/subject'
import Tinymce from '@/components/components/Tinymce'

export default {
  //声明组件
  components:{Tinymce},

  data(){
    return{
      saveBtnDisabled:false,
      courseInfo:{
        title: '',
        subjectId: '', //二级分类id
        subjectParentId:'', //一级分类id
        teacherId: '',
        lessonNum: 0,
        description: '',
        cover: '/src/assets/404_images/404.png',
        price: 0
      },
      courseId:'',
      BASE_API: process.env.BASE_API, //接口API地址
      Teacher:[],
      subjectOneList:[],
      subjectTwoList:[]
    }
  },
  created() {
    //获取路由中的id值
    if(this.$route.params && this.$route.params.id ) {
         this.courseId =  this.$route.params.id
         this.getCourseInfo();
    }else{
      this.getListTeacher();
      this.getoneSubject();
    }
  },

  methods:{
    getCourseInfo(){
      course.getCourseInfo(this.courseId)
      .then(response=>{
        console.log(response)
       this.courseInfo = response.data.courseInfo;

        //查询所有的分类，包含一级和二级
        subject.getsubjectList()
        .then(response=>{
          //获取所有一级分类
          this.subjectOneList = response.data.list

          //把所有一级分类的数组，进行遍历，比较当前courseInfo和所有的一级分类id，找出相同的对应id
          for (let i = 0; i < this.subjectOneList.length; i++) {
            var subjectdata = this.subjectOneList[i]
            if(subjectdata.id == this.courseInfo.subjectParentId){
                     this.subjectTwoList = subjectdata.children
            }
          }
        })

        this.getListTeacher()
      })
    },
    //上传封面成功
    handleAvatarSuccess(res,file){
      //上传服务器成功之后，将服务器中的图片地址，赋值给img的src，来做回显
      this.courseInfo.cover = res.data.url
    },
    beforeAvatarUpload(file){
       const isJPG = file.type === 'image/jpeg'
       const isLt2m = file.size / 1024 / 1024 < 2

       if(!isJPG){
         this.$message.error('上传头像图片只能是 JPG 格式')
       }
       if(!isLt2m){
         this.$message.error('上传头像图片大小不能超过2MB')
       }
        return isJPG && isLt2m
    },
    //查询所有的一级分类
    getoneSubject(){
      subject.getsubjectList()
      .then(response=>{
        this.subjectOneList = response.data.list
      })
    },
   //点击一级分类所有二级分类
    subjectLevelOneChanged(value){
       //value就是一级分类的id值
      for (var i=0;i<this.subjectOneList.length;i++){
        var onesubject = this.subjectOneList[i]
              if(onesubject.id === value){
                this.subjectTwoList = onesubject.children
                //把二级分类清空
                this.courseInfo.subjectId = ""
              }
      }
    },
    //查询所有讲师
    getListTeacher(){
       course.getListTeacher()
      .then(response=>{
        this.Teacher = response.data.items
      })
    },
    //添加课程
    addCourse(){
      course.addCourseInfo(this.courseInfo)
        .then(response=>{
          this.$message({
            type:'success',
            message:'添加课程信息成功'
          })
          //跳转到第二步
          this.$router.push({path:'/course/chapter/'+response.data.courseId})
        })
    },
    updateCourse(){
      course.updateCourseInfos(this.courseInfo)
      .then(response=>{
        this.$message({
          type:'success',
          message:'修改课程信息成功！'
        });
        this.$router.push({path:'/course/chapter/'+this.courseId})
      })
    },
      next(){
        //判断是添加还是修改
        if(this.courseInfo.id){
          //修改
          this.updateCourse();
        }else {
          this.addCourse();
        }
      }
  }
}
</script>

<style scoped>
.tinymce-container{
  line-height: 29px;
}
</style>
